Fans of the HBO show know him as Gavin Belson, but acting may soon be a footnote in his career.

After stints on HBO’s “Silicon Valley” and “Big Love,” Matt Ross is a familiar face. But if he has his way, that will soon change.

“I don’t want to be ungrateful, but the truth of the matter is that I don’t really audition or pursue acting at this point in my life,” he said. “Television has allowed me to not take on directing jobs I don’t want to take. I can cobble together a living.”

While Ross is wonderful as scheming tech executive Gavin Belson on Mike Judge’s hit show, and was memorable as polygamous cult henchman Alby Grant, he’s determined to define himself as a director. He made his debut in 2012 with microbudget romance “28 Hotel Rooms,” but “Captain Fantastic” is a picture window into the career that the 46-year-old Ross envisions for himself. A decidedly more polished work starring Viggo Mortensen, the film opens this week after gathering accolades at Sundance and Cannes.

As a teen, Ross aspired to acting, but experienced “a seismic shift” as a graduate student studying filmmaking at NYU. ”There’s something about it for me where I need to control my take on the world,” he said. “It’s a scary climate. We live in a world dominated by a certain kind of movie. The studios seem to be contracting wildly in what they will make.”

Fortunately, Ross didn’t need the studios for “Captain Fantastic,” which was shepherded by veteran producing duo Lynette Howell and Jamie Patricof (“Blue Valentine”) and acquired by Bleecker Street, a company steadily building its name with upscale commercial titles such as last year’s “Trumbo.” For some audiences, “Captain Fantastic” falls right into that sweet spot: Mortensen plays patriarch Ben, who raises his six children under experimental conditions in the woods of the Pacific Northwest, only to confront civilization with the news that his estranged wife has committed suicide.

As Ben and his brood return to society, the resulting odyssey veers from awkward comedy to philosophical treatise on different approaches to family life. Despite its darker elements, “Captain Fantastic” is ultimately a crowdpleaser about communal bonds — whatever your take on Ben’s unorthodox parenting.

“When I was young, I listened to punk rock music and thought life-negating things,” Ross said. “I wanted to make something that was more life-affirming. There are people who think things can change for the better. This film has hope in addition to its anti-authoritarian streak.”

“Captain Fantastic”

Erik Simkins / Bleecker Street

Ross, who spent part of his childhood on California communes, said while the story isn’t autobiographical, he drew on firsthand experiences for scenes in which Ben’s family enjoys an idyllic woodland existence and jams by the fire after dark.

“There was this desire to work in harmony with the natural environment,” he recalled, but was quick to point out that his family also spent time in India and Africa. “I wasn’t a sheltered hippie kid,” he said. “The thing that’s autobiographical is really that I felt very strongly the need to leave and be around kids my own age.” That’s where “Captain Fantastic” ultimately winds up, as family members consider their next moves. Referencing his own young children, Ross added, “This movie is far more about being a parent.”

Beyond that, it’s also proof of Ross’ ability to craft a polished, immersive cinematic experience. If there’s a through line in Ross’ first two features, it’s in his ability to create immersive environments whether it’s a drab hotel room or a woodsy terrain. While his screenplay juggles an ensemble cast with ease, the movie also bursts with vibrant colors and visually striking landscapes that take Ben’s sense of dislocation into an expressionistic realm. He said he spent hours at a photography store in Los Angeles, combing through images that fit his needs. “I wanted something that looked close to the real world,” he said.

In spite of all the time he invested in the project, Ross has yet to merge his two professions. He’s coy about the idea of directing an episode of “Silicon Valley,” something his agents have asked him about more than once (he’s also been approached about turning both of his movies into series). “They hired me as an actor,” he said. “The last thing they want to hear about are my extracurricular activities.”

“Captain Fantastic”

Bleecker Street

But viewers who recognize him on the street as Gavin Belson are a different story. “About 90 percent of the time, I’m fine with it, because it’s coming from their enthusiasm and love for ‘Silicon Valley,’” he said. “Maybe it’s different if you can’t go outside because you’re a movie star. I’m not that. In some ways, their enthusiasm has less to do with me than the show.”

Still, he added, “about 10 percent of the time, it’s aggravating, because it really has nothing to do with me.” Ross wants people know that he’s not just his character — or, rather, he’s not the one that they think they know.

That 10 percent was on full display at a recent party hosted by the Seattle International Film Festival, where Ross was in town to promote “Captain Fantastic” but found himself accosted by hordes of selfie-seeking fans. One eager-faced young man could barely contain himself. “You play Gavin Belson, don’t you?” he asked. “You look just like your character!”